Railway traffic controlling apparatus



July 28, 1931. H. A. THOMPSON 1,816,302

RAILWAY TRAFFIC CONTROLLING APPARATUS Filed OOt. lO, 1929 ATTORNEY Patented July 2.8, 1931` AiJNiTED STATES PATENT OFFICE g HOWARD A. THOMPSON, F EDGEWOOD BOROUGH, PENNSYLVANIA, ASSIGNOR TO THE i yUNION SWITCH & SIGNALy COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORA- TION OF PENNSYLVANIA n vRAILWAY TRAFFIC co'NTRoLLING APPARATUS lApplication led October 10, 19729. Serial No. 398,660.

This invention relates to railway traffic' controlling apparatus; One of the vfeatures of the invention comprises provisions for supplying train control energy to the rails adjacent both ends of a section ofrailway trackby asingle coding device. The invention also includes means for bringing the coding device into action in response to the entry of a train into the track section and for causing said device to apply energy to each end of the section in accordance with trafric conditions beyond said end. Another feature of the invention resides in provisions whereby the coding device may control the impedance of a track relay circuit so as to prevent energization of the track relay when energy is supplied to the adjacent end of `the section and so that the track'relay may on the other hand be'energized in response to the application of energy tothe opposite end of the section, following the vacating of said section by a train. Other features of the invention will be hereinafter described and claimed. I

In the accompanying drawings Fig. 1 is a diagrammatic view illustrative of my in- Y vention and Fig. 2 is a diagrammatic view of a modification.

Similar `reference characters refer to similar partsin both views.

Referring tothe drawings, thevnumeral 5` designates a section of railway trackto one end of which is connected a track relay 6 and to the other end of which section the sec-- ondary of a transformer 7 is connected. One

terminal of the primary of the track transformer 7V is shown connected through wire 9, armature and front contact 11 of track relay 6, and wire 12 to'one terminal of the secondary of the line transformer 8. Y The other terminalrof the secondary of said line transformer is connected throughvwires 13 and 14 to the second terminal of the primary of the track transformer 7. The latter is thus normallyfed by said line transformer. 'lhe localelement 6 of the track relay isv permanentlyy energized from line transformer 8, through wires 15', 16 connected tothe wires 12, 13, respectively, as shown; while the track element 6 of said relayis permanently connected to the rails at the right hand end of the track section in series with the primary winding 17 of impedance transformer17. Whenthe track section is unoccupied, the

secondary winding 17 of impedance transformer 17 is short circuited through wires 18 and 19, front contact 20 and armature 21 of track relay 6, and wires 22 and 23.

When a train enters the track section it shunts the track element 6 of the relay 6. thus de-energizing the same. Such de-en ergization of the track relay results .in the disengagement of armature 21 from front contact 20, with Yconsequent opening of the shunt circuit for the secondary 17 of the limpedance transformer 17 Also, the afore- -said de-energization of the track relay results inthe disengagement of armature 10 from front contact 11 and the engagement of said armature with back contact 24. The latter is connected by a wire 25 with an armature 26 of a relay 27, which relay is'responsive to trailic conditions to the left ,of section 5; said relay 27 being energized when said traiic. conditions are safe and de-energized Ywhen saidc'onditions are unsafe.`V Re# lay 27 may be controlled in accordance with the direction of travel as well as the location of trains, etc., to the left of section 5, and these features are all includedl in the term traffic conditions. Sinceconnections for rendering relay 27 responsive to traffic condi'tions as' above setforth are well known in tor 31 is operatedfis moved alternately into engagement with two fixed contactsk 50 and 51 at a different frequency from the fre? quency of operation of contact 49. Operatively connected with contact element 48 and moving in synchronism therewith is a contact element 30 arranged to engage a fixed contact 36 each time contact 4 50 is closed.

Vhen relay 27 is energized, its armature 26 engages front contact 28 which is connected by wire 29 with contact element 30 of motor coder 31. The contact 36 of the motor coder connected by a Wire 37 with a back contact 38 of relay 6, which contact 38 is engaged, when relay 6 cle-energized, by armature 39 connected With Wire 12` It will thus be seen that when the track relay 6 is ile-energized as aforesaid, while the relay 27 is energized, the primary of the track transformer 7 is connected to contact element 30 of the motor coder, so that each time that said contact element 30 engages contact 36, current from the line transformer 8 flows throng-h the primary of said track transformer; the circuit being' from one terminal of the secondary of line transformer 8, through Wires 13 and 14, the primary of track transformer- 7, Wire 9, armature 10 and back contact 24 of relay G, Wire 25, arnlature 26 and front contact 28 of relay 27, Wire 29. contact element 30 and contact 36 of motor coder 31, wire 37, back contact 38 and armature 39 of relay 6, and Wire 12 to the other terminal of the secondary of the line transformer. It will thus be evident that When the track relay is cle-energized, with relay 27 in energized condition, current impulses of a frequency correspondlng` to the number of engagements unit time of contact element 30 with Contact 3G will be supplied to the track transformer 7. If relay 27 is deenergized at the time the track relay is de-energized, current is supplied continuously from line transformer 8 to track transformer 7 through a circuit passing' from transformer 8 through Wires 13 and 14, the secondary of track transformer 7 Wire 9, armature 10 and back contact 24 of relay 6, Wire 25, armature 26" and back contact 40 of relay 27, Wir-e 41, and Wire 12 back to transformer 8. Thus upon de-enei'gization of the track relay by the entry of a train into the track section 5, there supplied to the transformer 7,A and hence to the rails of said section, energy in the form of current impulses corre sponding to the operation of Contact element 3() of the motor coder or in the .form of a continuons uninterrupted flow of current, dr-:pendinn,` upon Whether the relay 27 is cnergized or tlc-energized, which in turn depends upon traffic conditions to the left of said track section In other Words, upon de-enerpization of track relay 6 energy in a form correspondnfr to traliic condwons to the left of the track section 5 is supplied by the track transformer 7 'to the rails at the left hand end of said section.

A code feeding transform-er 42 is adapted to feed coded energy to the rails at the i ,eli

hand end of track section 5 in response to the entry of a train into said section. One terminal each of the primary 42 of transformer 42 and the secondary 17 of impedance transformer 17 are shown connected together by the Wire 23, Which Wire is also connected to armature 44 of a relay 45. The other terminal of said primary 42 of transformer 42 is connected through Wires 43 and 13 to the secondary of line. transformer 8. The relay 45 is responsive to traffic conditions to the right of section 5; being energized When said conditions are safe and de-energized when they are unsafe. The armature 44 is adapted to engage either a front contact 46 or a back contact 47 of relay 45; Which contacts 46 and 47 are connected respectively to contact elements 48 and 49 operated by the motor coder. The contacts 50 and 52 of the motorcoder are connected to the previously mentioned Wire 19 connected to the secondary of transformer 17 While the contacts 51 and 53 are connected to Wire 37 previously described as connected to back contact 38 of track relay 6.

It. Will now be seen if relay 45 is energized when the track relay 6 is cle-energized upon entry of a train into the track section 5, current from the line transformer 8 is supplied to the code feeding transformer 42 each time it contact element 48 of theA motor coder engages contact 51, the circuit for said current being' from one terminal of the secondary of line transformer 8 through Wires 13 and 43, the primary of transformer 42, Wire 23, armature 44 and front contact 46 of relay 45, contact element 48 and contact 51 of the motor coder,` Wire 37,V back contact 38 and armature 39 of track relay 6, and Wire 12 to the other terminal of the secondary of line transformer 8. Current impulses of a frequency corresponding to the number of engagements per unit time of element 48 and contact 51 are thus supplied to transformer 42` and thence to the rails at the right hand end of track section 5, said impulses indicating that traiiic conditions to the right of said section are safe. It Will be noted that at the time contactelement 48 engages contact 51 it is disengaged from contact 50 and the secondary 17"l of vimpedance transformer 17 is open circuited; whereby the impedance of the Winding' 17 of said transformer, which is in series with Winding 6 of the track relay 6, is increased sufficiently to prevent any substantial energization of said Winding,` 6 by the aforesaid current impulses supplied by transformer 42.

When track relay 6 and relay 45 are deenergized, current impulses are supplied to transformer 42, and thence to the rails, by line transformer 8,. by Way of the armature 44, wire 47 and motor coder contacts 49 and 53; said impulsesV being` of a frequency cor responding to the number ofv engagements per unit time of element 49 and Contact 53 ance of the primary 17 of said transformer' increased as above set forth to prevent any considerable amount of current from flowing through winding 6 ofthe trackrelay.

In addition to the kprevention of a sub-stantial flow of current through coil 6" by virtue of the impedance of transformer coil 17 when coil 17 is open circuited; the secondary winding 42 of transformer 42 may as a further precaution be sofconnected to coil- 6 that any current that does feed into the latter coil will be in a direction to open the track relay. However, the impedance of transformer winding 17, when winding 17 is open-circuited, is suiiicient to prevent energization of the track relay by the current supplied by the code-feeding transformer 42; so that said impedance suiiices by itself to prevent misoperation of the relay in re-sponse to the impulses supplied by said code-feeding transformer.

l/Vhen coder contact 48 or 49 is engaged with its associated lower contact 50 or 52 the secondary 17 of impedance transformer 17 is short circuited by way of wire 23, armature 44, contact 46 or 47, the'corresponding contact element 48 or '49 and its respective lower contact 50 or 52, wire 19 and wire 18. It should be noted that said secondary of transformer 17 is short circuited during the saine portion of the code cycle during which the primary of track transformer7 is energized. After the track section 5 is vacated, the track relay 6 will become energized during the next down stroke of motor coder contact'48 or 49, the secondary of impedance transformer 17 being at that time short circuited and the track element 6V of relay 6 receiving energy through the rails'froin track transformer 7. Armatures 21, 10, 35-and 39 are thereupon shiftedY tol their positions shown in Fig. 1, the

motor coder is de-energized, and the relay 6 is thereafter maintained energized by the uninterrupted current supplied tothe rails by transformer 7.

The contact elements 3() and 48 of the motor coder are driven in synchronism and engage their back contacts 36 and 50 respectively during the same interval; whereby current interrupted by contact element() is supplied by transformer 7 to the rails concurrently with the engagement of contact element 48 with contact 50. "While the contact element 49 is opera tedat a different rate from contact members 30 and 48, the latter are'driven considerably more rapidly than said element 49 (for example, saidfelement 49 may engage each of its associated contacts '52,k 53 alter-.`

nately times per minute'as compared with 180 engagements of each ofV contacts 50, 51 alternately by contact element 48, whichis operated in synchronism with element 30) and during each time that saidelement 49 engages its back contact 52, the member 30 will engage its back contact 36at least once. Thus, whether the secondary or'impedance transformer 17 be short circuited by contact element 49, or by the contact element 48, .the

track relay 6 ywill be energized by the first ,A

impulse applied to the rails by transformer 7 following the vacating of the track section 5.l Of course, if at the time the track section is vacated, uninterrupted current is being suplied by transformer 7 to the rails through armature 26 and back contact 40 of relay 27, the track relay 6v will likewise be energized as soon as the secondary of impedance transformer is short circuited by either contact element 48 or contact element 49.

While I have shown the track transformer 7 as supplying either interrupted current. or uninterrupted current to the railsl in response to de-energization of the track relay and depending upon the condition of relay 27, it will be evident that by connecting back contact 40 to a contact element driven by the motor coder at a different rate from element 30 (80 cycles per minute, for example) said transformer 7 may be caused to supply coded energy of a corresponding frequency to the rails when the relay 27 is de-energized- Such an arrangement is indicated in Fig. 2, wherein wire 41 is shown connected to a contact element 55 operated by the motor coder in synchronism with contact element 49 so as to be engaged with and disengaged from contact 56 at the same time that said element 49 is engaged with and disengaged from back contact 52. Contact 56 is connected to wire 37, so that each time said contact is engaged by element 55 an impulse of current is transmit-v ted to track transformer 7.

for supplying train control energy alternately to the respective ends of a track section byy a single coding device. The coded energy supplied to the rails by the transformers? and 42 respectively may be utilized in any suitable or convenient way as by the usual apparatus mounted on the'front ofthe locomotive and. responsive to current impulses applied It will beseen that Ihave provided meansV to the rails of the track section at a point f ahead of the train for causing indications correspondingte said impulses to be given in thel locomotive cab. It will be evident that by applying coded energy through trans# former 7 to the rails' at the left hand end of I the section in accordance withthe traffic conditions to the left of saidv section, a train entering said section from the right. and

equipped with the conventional receiving apparatus aforesaid will receive indications of Y iso will receive from the impulses applied to the rails by transformer 4Q indications of traffic conditions to the right oi said section.

The terms and expressions which I have employed are used as terms of description and not of limitation, and I have no intention, in the use of such terms and eioressions, of eX- cluding any mechanical equivalents of the features shown and described or portionsthereof, but recognize that various structural modifications are possible within the scope of the invention claimed.

What I claim is: 1. In combination, a section of railway track, means for applying uninterrupted current to the rails adjacent one end of said section, and means effective upon the entry of a train into the track section for applying coded train control. energy to the rails adjacent both ends of the track section.

2. In combination, a section of railway track, means for applying uninterrupted current to the rails adjacent one end of said section, and means effective upon the entry of a train into the track section for applying coded train control energy to the rails adjacent bot-h ends of the track section alternately.

3. In combination, a section of railway track, means responsive to entry oiu a train into said section, means controlled by the first mentioned means for applying impulses of train control energy to both ends oit said section, and means responsive to traffic conditions adjacent each end of said section for controlling the frequency of the impulses applied by the second mentioned means to the corresponding end of the section.

4. In combination, a section of railway track, a track relay for said section, means controlled by said relay for applying impulses of train control energy alternately to the respective ends of a track section, and relays responsive to trailic conditions beyond each end of said section forcontrolling the frequency of the impulses applied by said means to the corresponding end of the section.

5. In combination, a vsection of railway track, a track relay de-energizeo upon entry oi' a train into said track section, means controlled by said relay 'for applying train control energy to the ends oi said section, a transformer having a primary winding in circuit with said relay, and circuit for the secondary ot said transformer controlled by said energy applying means.

6. 'I` he method of controllingl train move- Gg ments in either ot opposite directions over a section of railway track, said i'ncthod consisting of applyingr coded train control energy to the rails adjacent both. ends ot. the section and ot controlling tlie characteristics c55 of the current applied to each end of this section in accordance with traffic conditions beyond such ends oi' the section.

7. In combination, a section of railway track, means for transmittingl coded energy, and means eiiective upon the entry of a train into the track section for causing' said lirst mentioned means to apply coded energy to the rails adjacent both ends of the track section.

8. In combination, a section of railway track, a coding device, and means responsive to the entry of a train into the track section for causing said coding device to supply coded energy to the rails adjacent the respective ends of said section.

9. In combination, a section ot' railway track, a coding` device, and means responsive to the entry of a train into the track section for causing said coding` device to supply coded energy to tlic rails adjacent the respective ends of said section alternately.

l0. In combination, a section of railway track, a coding device, means tor at times causing said coding device to supply coded energy to the rails adjacent the respective ends of said section, and means responsive to traiiic conditions adjacent each end 01"' said seccion for controlling the application of energy by said coding device to the corresponding end of the section.

1l. In combination, a section of railway tracl' a coding device, means responsive to the entry of a train into the track section for causing said coding device to supply coded energy to the rails adjacent the respective ends of said section, and means responsive to trafiic conditions adjacent each end oi' said section for controlling the application ot' energy by said coding device to the corresponding end of the section alternately.

12. In combination, a section of railway track, a coding device, means including a contact controlled by said coding device for supplyingl coded energy to the rails adjacent one end of said track section, means including another contact controlled by said coding device `for supplying coded energy to the rails adjacent the other end of said track section, and means responsive to tne entry of a train into said section tor controlling said coding device.

i3. In combination, a section oit railway track, a coding device, means including a set of contacts controlled by said coding device for supplying coded impulses oit diiier'ent characteristics to the rails adjacent one end of said track section, means including another set of contacts controlled by said coding device for supplying coded impulses of difri'crent cliaracteristics to the rails adjacent the other end of said track section, and means responsive to traffic conditions adjacent each end of the track section 'for letcrmining the characteristics or". the imp nlscs applied b ysaid 'los @grasos c coding device to'the corresponding end of said section.

14. In combination, a section of railway track, track relay, means for connecting said relay across the rail adjacent one end ofthe section, a coding device controlled by said relay for applying coded train control energy to the rails adjacent the ends of said section, and means controlled by said coding device, for increasing the impedance of the track relay circuit concurrently'with the application of coded energy to the end of the section adjacent said track relay.

15. In combination, a sectionV of railwayl track, a track relay, meansk for connecting said relay with the rails adjacent one endv of said section, a` coding device controlled by said relay-'for applying coded train control energy to the rails adjacent the ends of said section alternately, and means controlled by j said coding devicefor increasingthe impedance of the track relay circuit concurrently with the application of coded energy to the end of the section adj acent'said track relay.

16. Ink combination, a section of railway f track, a track relay, means for connecting said relay with the rails adjacent one endv ofV said section, 'a coding device controlled by said relay for applying coded train control energy to the rails adjacent the ends of said section, and means comprising contacts operated lsynchronously by said coding device for decreasing thel impedance of vtrack relay circuit concurrently with/the application'of energy to the end of the section opposite said track relay. Y l

17. In combination, a section of railway track, a track relay, meansfor connecting said relay with the rails adjacent one end of said section, a coding device controlled by said relay for applying coded train control Y energy to the rails adjacent the ends of'said section alternately, and means comprising contacts operated synchronously by said coding device for decreasing the vimpedance of l the track relay circuit concurrently with the application of energy to the end of the section opposite said track relay.

18. In combination, a section of railwaytrack, a coding device comprising two Contact l elements operating in synchronism, means controlled by one contact element for supplying coded energy tothe rails adjacent one end of the section, and means controlled by the other contact element for supplying coded energy to the rails adjacent the other end of the section, whereby coded energy is supplied to the two ends of the section alternately.

19. In combination, a section of railway track, a transformer, a track relay connected across the rails adjacent one end of said section through one winding of said transformmeans for normallyy supplying uninterthe rails adjacent the'other rupted current to end of the section, a coding device comprising a first contact and a second contact opertrol energy to said other end of the section over said first contact and to supply coded train control energy to saidone end of the `'section over said third contact, a first circuit for the remaining winding of said transformer including a front contact'of said track relay, and asecond circuit `for said remaining transformer winding kincluding said second contact.

In testimony whereof, I have signed my name to this speciiication this v7th day of Ocaber, i929. Y

y Howiiiin A. THOMPSON, 

